2001 waterfowl breeding population and habitat survey for South Dakota and North Dakota

              2001
WATERFOWL BREEDING POPULATION SURVEY
FOR
SOUTH DAKOTA AND NORTH DAKOTA
Williston
Dickinson
Garrison
Bismarck
Minot Devils Lake
Grand
Forks
Jamestown Fargo
Aberdeen
Water-town
Sioux Falls
Madison
Huron
Mitchell
Pierre
Camp Crook Mobridge
Belle Fourche
Rapid City
49
44 48
46
43 47
45
TITLE: Waterfowl Breeding Population and Habitat Survey for South and
North Dakota
STRATA SURVEYED: 44, 48, 49 (South Dakota)
43, 45, 46, 47 (North Dakota)
DATES: 2 - 4 May 2001 (43 and 44)
7 - 28 May 2001 (45, 46, 47, 48, and 49)
DATA SUPPLIED BY: United States Fish and Wildlife Service
Strata 45, 46, 47, 48, 49
Aerial Crew
Observer/Pilot - John W. Solberg, Flyway Biologist, WPS/DMBM, Bismarck, ND
Observer - Sue Thomas, Secretary, MBHP, R-1, Portland, OR
Ground Crew
Leader - George Allen, Wildlife Biologist, BSA/DMBM, Arlington, VA
Assistants -
Monte Ellingson, Private Lands Biological Technician, Crosby
WMD, Crosby, ND
Pam Garrettson, Wildlife Biologist,
PHAS/DMBM, Laurel, MD
Fritz Prellwitz, Wildlife Biologist,
Bowdoin NWR, Malta, MT
Strata 43 and 44
Aerial Crew
Observer/Pilot - James F. Voelzer, Chief - WPS/DMBM, Portland, OR
Observer - Ray Bentley, Flyway Biologist, WPS/DMBM, Corvallis, OR
Ground Crew
Leader - Allison Arnold, Wildlife Biologist, EPIC, LLC, Dripping Springs,
TX
Assistants - Vincent Griego, Wildlife Biologist, Salton Sea NWR, Calipatria,
CA
ABSTRACT: The 2001 Waterfowl Breeding Ground and Habitat Survey for South and North
Dakota was conducted 7 - 28 May with standard aerial coverage accomplished. Personnel
changes occurred this year in both the air and ground crew. Habitat conditions were good to
excellent through out most of the crew area. Compared to 2000 levels, wetland counts increased
58% in South Dakota and were similar (2%) in North Dakota. Waterfowl breeding populations
were second and third highest of record for South Dakota (4.301 million) and North Dakota
(5.767 million), respectively. The outlook for waterfowl production in 2001 is above average.
Selected information for 2001 is presented below:
South Dakota
2001 Indices Percent Change From
(thousands) 2000 1991-2000 mean 1959-2000 mean
Mallard 1040.5 -6% 28% 128%
Gadwall 508.9 -20% 7% 133%
Blue-winged Teal 1608.7 2% 25% 96%
Northern Pintail 385.4 92% 89% 75%
Redhead 51.0 54% -9% 8%
Canvasback 5.1 -24% -27% -20%
Total Ducks 4301.1 6% 29% 104%
May Ponds 989.1 58% 38% 88%
North Dakota
2001 Indices Percent Change From
(thousands) 2000 1991-2000 mean 1959-2000 mean
Mallard 1484.3 NC 53% 163%
Gadwall 780.3 -37% 14% 122%
Blue-winged Teal 1688.7 -41% 26% 101%
Northern Pintail 377.0 44% 32% 9%
Redhead 226.4 -26% 17% 68%
Canvasback 66.5 219% 73% 130%
Total Ducks 5767.4 -22% 35% 108%
May Ponds 750.2 2% -13% 3%
METHODS: The procedures followed in conducting the survey are described in the Standard
Operating Procedures for Aerial Breeding Ground and Habitat Surveys in North America,
Section III, revised 1987. There were no changes in survey coverage (Tables 3 and 6) and all
transects were flown. Survey end time (12:00 noon), as outlined in the operating procedures, was
violated on two days. In these instances, a late departure (due to foggy conditions), resulted in
the completion of sampling no longer than 1.5 hours past the cut-off time. The decision to
violate the operating procedures sampling time was made in attempt to minimize the late date of
survey completion in the crew area.
Personnel changes involved both the air and ground crew in 2001. Pam Garrettson, a wildlife
biologist with the DMBM in Laurel, Maryland, joined the east river ground crew this year. Pam
worked last year assisting with ground crew activities in the western Dakota/Montana survey
area. Fritz Prellwitz, a wildlife biologist from Bowdoin NWR, also provided his able assistance
completing ground survey activities. Sue Thomas, from the Migratory Birds and Habitat
Programs office in Portland, Oregon, participated as a first year aerial observer. Remaining air
and ground personnel were unchanged since 2000. All new members received pre-survey
training/review sessions relating to air and ground procedures. Participants were critiqued
regarding species identification, judgement of transect width, and adherence to standard
operating procedures.
Visibility Correction Factors (VCF’s) in the crew area are typically calculated using observations
collected from 17 air/ground comparison segments. All comparison segments in the crew area are
co-located with operational survey segments and this year, all were completed. The VCF for
wetlands, established by comparison of air and ground observations, was 1.06. Wetland counts
and all other data are considered comparable to all years when VCF’s were determined.
Transect flying was accomplished in a wheeled Cessna 185. The survey required 70 hours of
flight time including aerial observer training, reconnaissance, and the collection of footage for
the “Status of Waterfowl” video. For the second time in the crew area, on-board computers,
interfaced with the aircraft GPS, were used to record waterfowl and wetland observations. With
each observation, time and location information were also captured. Transect flying commenced
7 May in the eastern Dakotas and was completed 28 May. Once the survey was initiated, 7 days
were forfeited to adverse weather. The common culprit this year was wind, which exceeded 50
mph on numerous occasions. Information from Stratum 43 and 44 was collected 2 - 4 May by
the Montana survey crew led by James Voelzer. Our appreciation is extended to that crew for
their efforts and contributions of data and habitat information from the Western Dakotas.
WEATHER AND HABITAT CONDITIONS:
The crew area entered the fall of 2000 with the extreme northwestern portion of North Dakota
considered abnormally dry. Similar conditions existed in much of the southern 2/3rds of South
Dakota. In fact, southern fringes of the southeastern and south central regions of South Dakota
were considered in first stages of drought.
Temperatures during September and October were generally above normal. Benefits from
precipitation received early during this period were negated by warm winds and evaporation.
Late in October and particularly in northern areas, heavier rains arrived. Portions of North
Dakota received up to four times normal precipitation for the month. Rains continued into the
first week of November.
Atypical for this late in the season, clashing air masses in early November spawned tornadoes in
the Bismarck area. The second week of November ushered in a cold snap, freezing most
wetlands and causing a major exodus of waterfowl from Canada and the Dakotas. By the end of
November, the majority of the crew area was snow covered, with larger amounts occurring in
South Dakota.
Although December was windy and bitter cold (wind chill temperatures commonly -40° to -50°
F), little snow was received. Temperatures in January moderated to normal or slightly above for
the season. North Dakota received little snow during the month but South Dakota (and points
south to Oklahoma and Arkansas) continued to experience major snow/winter events. A major
storm front passed through South Dakota during the last week in January, strongly increasing
precipitation levels in the south to 200 - 400% of normal, reversing the trend in moisture levels
between the two states as North Dakota received 25 - 50% less precipitation than normal for the
month.
In February, temperatures returned to average. Snow continued to fall, again with larger amounts
in South Dakota, and by months end, snow cover from 5" - 40" covered the entire crew area.
Huron, SD reported a record season-to-date snowfall of over 80". By mid-March, temperatures
climbed above normal and an 8 to 9 day snow melt occurred. Scattered rains began by the end of
the month. Showers continued in April and though temperatures were cool, thawing continued
and some flooding of roads and rivers occurred.
During May, weather conditions were generally windy and warm. Scattered showers occurred in
South Dakota, but North Dakota received little rain. Temperatures turned colder than normal in
both states for the closing of May.
SOUTH DAKOTA (St. 44: 2 - 3 May, St. 48, 49: 7 -13 May)
Stratum 44 - Although the 2001 wetland index decreased -35%, -48%, and -32% from last year,
and the ten-year and long-term means, it was reported that residual nesting cover was above
average and pond levels were nearly full. Additionally, CRP was conspicuous in all portions of
the stratum. New growth of grasses was slightly behind normal, but the aforementioned cover
was adequate for nest initiation. Overall , habitat conditions in the stratum are considered good
and production should be average to slightly above average.
Stratum 48 - Recall that portions of Stratum 48 from Redfield/Huron south were quite dry in
2000. A dramatic recovery in wetland conditions occurred in Stratum 48 where the wetland
index increased 73% since last year. Not only were the more persistent wetland types improved
in quantity and quality, but the reappearance of temporary and seasonal wetlands was reminiscent
of the mid to latter 1990's. Many areas in the southern half of the stratum were too wet for spring
agricultural activities and by the completion of the South Dakota portion of the survey, had not
yet been affected by farming. Because of the wet conditions, plowing of large quantities of field
stubble or wetland basin margins and no ditch/field burning was observed. In the northern 1/3 of
the stratum, comparatively less temporary water was evident and farming activities were farther
advanced than in the south. In this region, eruption of current year crop had occurred by mid-
month and despite farming activities, residual cover was present in good supply. Overall
conditions in the stratum are considered good to excellent. Compared to the ten-year and long-term
averages, the 2001 wetland index was 59% and 131% respectively. Particularly
considering the improvements in the southern portion of the stratum, above average production is
expected this year.
Stratum 49 - The entire stratum possesses good to excellent habitat conditions where wetland
counts increased 126% since last year. Particularly in the south central region, much
temporary/sheet water exists, which has curtailed agricultural activities. Nesting cover in the
stratum has been slow to develop, but residual supplies are in good standing. Cover/water
combinations in the Prairie Coteau, as well as “west river” areas of the southwest, are also
providing attractive habitat. The 2001 wetland index is 97% above the ten-year average and
150% above the long-term average. Waterfowl production from Stratum 49 is expected to be
above average.
NORTH DAKOTA (St. 43: 3 - 4 May, St. 45, 46, 47: 15 - 28 May)
Stratum 43 - The west river survey crew rated the north, central and eastern portions of the
stratum as good for nesting and production while the extreme western and south central portions
only fair. Because the former is the most productive portion of the stratum, average production is
expected in Stratum 43. Residual nesting cover was adequate over most of the stratum; the
extreme western portion and the extreme south central parts being the exception. For the first
time in over a decade, CRP was noticeable by it’s presence and will contribute to production this
year. In the past, the west river crew has observed that haying and grazing reduced the
effectiveness of CRP to annual waterfowl production. Water counts decreased -18% from the
2000 level and remain -41% and -26% below the ten-year and long-term figures.
Stratum 45 - Wetland numbers in Stratum 45 improved slightly (14%) compared to 2000.
Generally, the eastern third of the stratum, and particularly the Devils Lake region, offer
excellent conditions. Many acres in the Devils Lake area have been too wet for spring tillage and
may not be planted this year. Moving west, the central third offers good conditions with the best
combinations of cover and water occurring in southern portions of the Missouri Coteau.
Although the coteau is somewhat drier than it was in the mid to late 1990's, water/cover
combinations are still good as is the potential for waterfowl production. Northwestern Stratum
45, in the coteau slope, is relatively drier and exhibits less available cover. We considered
habitat conditions in this region only fair. The 2001 wetland index for Stratum 45 is similar to
the ten-year average (-1%) and the long-term average (7%). We anticipate waterfowl production
in the stratum to be average or above.
Stratum 46 -The southeast portion of Stratum 46 provided noticeable improvements in wetland
conditions compared to last year. Wetland numbers in the remainder of the stratum were similar
to last year. As in Stratum 45, the Missouri Coteau in Stratum 46 is slightly drier than in recent
past years, but still looks good. As usual, the highest potential for waterfowl production occurs
in this region, based on wetland/nesting cover combinations. Overall habitat conditions in the
stratum are considered good, with small areas in the southeast and north central considered
excellent. The wetland index for 2001 was similar (-8%) to the 2000 figure, decreased (-15%)
compared to the ten-year average, and was above (13%) the long-term mean. The potential for
waterfowl production in the stratum is above average.
Stratum 47 - Admittedly, Stratum 47 offers relatively little in terms of potential waterfowl
production. Precipitation during the past annual cycle benefitted the region, resulting in a 14%
increase in the wetland index since 2000. The 2001 wetland index is below the ten-year average
(-18%) and similar to the long-term average (3%). Agricultural intensity and cropping patterns
are generally detrimental to nesting cover and increases predator efficiency. Habitat conditions
in the stratum range from fair (in the north) to excellent (in southern reaches. Realizing the low
relative contribution potential offered by 47, waterfowl production is expected to be average this
year.
DISCUSSION/BREEDING POPULATION ESTIMATES: Precipitation received since last
year’s breeding season erased wetland deficits in South Dakota, east of the Missouri River (Table
2). The return of temporary and seasonal water in the southern half of Stratum 48 and in south
central Stratum 49, was dramatic. In these areas, conditions were so wet, essentially no farming
activity (other than aerial) had commenced by mid-May. As a result, field stubble from the 2000
growing season was untouched. Additionally, no burning of ditches or wetland margins was
observed here. North of Huron, habitat conditions were more similar to last year. Vegetation
development, farming activities, and crop development were farther advanced than in the south.
All types of nesting cover were in good supply for breeding waterfowl in South Dakota.
In North Dakota, we believe that improvements in wetland conditions in some areas were off-set
by losses in other areas. Improvements resulting from precipitation affected primarily the eastern
areas (most of Stratum 47, southeastern 46, and northeastern 45). Conditions on the west side of
the “east river” crew area were drier than last year. This was evident in the Missouri Coteau
(excellent cover but less water than in the mid to late 1990's) and in the coteau slope region
between Williston and Parshall. Even though the west river survey crew reported an -18%
decline in Stratum 43 and our counts in Stratum 46 (-8%) followed a similar trend, the statewide
wetland index remained similar to last year (2%) and the long-term average (3%, Table 5).
Mirroring the trend of plant phenology, waterfowl breeding activities appeared to be slightly later
in southern South Dakota compared to the northern part of the state and in North Dakota. In the
northern areas, breeding activities were more “normal” or at least farther advanced. Based on our
observations in the south, along with reports of Canada geese nesting 7 to 10 days later than last
year, we elected to postpone our survey initiation until the 7th of May. At the onset, drake to pair
ratios of early nesting mallards and pintails were acceptable (something close to 50:50). As our
sampling progressed into the northern quarter or third of South Dakota and into North Dakota,
the numerator of the ratios increased at a faster than expected rate. Arriving in Jamestown, we
were “pinned down” by a strong, slow moving low pressure system that provided 4 to 5 days of
35 - 50 mph winds. Missing these days of survey, further aggravated the problem of survey
timing for the early nesting species. By the time we completed the survey in extreme
northwestern North Dakota, we observed some large flocks (10 - 20) of male mallards and
pintails. Based on our observations, we feel that our overall survey timing for early nesting
waterfowl in east river South and North Dakota, was slightly late. For the crew area, drake to
pair ratios for mallards were 63:37 for both states. The pintail ratio in South Dakota was 59:41
and in North Dakota, 67:33.
To illustrate the intensity of nesting activities in the Dakotas, we will again examine preliminary
information from nest searching on two areas. In Brown County, near Sand Lake NWR in South
Dakota, an 80 acre predator exclosure was monitored again this year. Service biologists reported
that on 23 April, a storm blanketed the area with 10" of snow. This event caused some nest
abandonment/loss. By mid-June, three rounds of nest searching had been completed. A total of
180 nests (-15% from 2000) were located for their efforts. Near Medina, North Dakota (in the
Missouri Coteau in Stratum 46), Service biologists had located 60 nests by late June in a 70 acre
exclosure. These nests represent a -25% decrease compared to the 80 nests found in 2000. The
biologists commented that late nesting activity appeared low at the North Dakota site. Despite
the decline in nest numbers since last year (granted, only 2 areas), the 1 to 2 nests per acre, in
these two exclosures, are impressive.
In South Dakota, the second highest waterfowl breeding population index of record (4.301
million) was observed. The 2001 total duck index is essentially unchanged (6%) from the 2000
figure and is 29% and 104% above the respective ten-year and long-term averages (Appendix 1).
For the fifth year running, the mallard index exceeded one million birds, falling just short (-6%)
of the 2000 index. Blue-winged Teal posted a new record high, exceeding 1.6 million birds.
Pintails too, responded to the excellent habitat conditions and increased 92% from last year’s
index. All species of dabbling ducks in South Dakota were at or above ten-year and long-term
means. In the diver group, only Redhead (54%) and Bufflehead (58%) increased since last year.
All divers except Canvasback (-20%) and Bufflehead (-60%) were above long-term averages in
2001 (Table 1).
The total index for breeding waterfowl in North Dakota in 2001 was 5.767 million birds
(Appendix 2). This represents a -22% decrease from last year’s figure. The 2001 index for
mallards was unchanged from last year and is similar to the 1999 record index. As in South
Dakota, pintails responded positively to the good/excellent habitat conditions in North Dakota by
increasing nearly 44% since 2000. Significant decreases, since last year, were recorded for
Gadwall (-37%) and Blue-winged teal (-41%), which were major contributors to the overall
decline (-22%) in the dabbler group. Although Canvasback (-26%), Scaup (-27%), and Ruddy
Ducks (-13%) all declined since last year, all members of the diver category with significant
sample sizes, remained at or above the ten-year and long-term levels (Table 4).
CONCLUSIONS:
1. Following a winter of generous precipitation, wetland conditions in South Dakota
rebounded since the spring of 2000. Compared to last year, the statewide wetland index
increased 58%. Most noticeable was the return of water in the southern half of Stratum
48 and the south central region of Stratum 49. The water index is 38% above the ten-year
average and 88% above the long-term mean. Although current year vegetation
development was slightly later than normal, residual nesting cover in and around wetland
basins, that associated with agricultural fields, and CRP, offer abundant supplies of
nesting areas. Total breeding waterfowl recorded showed little change (6%) from last
year but is the second highest index of record. Mallards (-6%) were similar to the 2000
index and remained above one million birds. Attracted to the improved conditions,
northern pintails exceeded last year’s index by 92% and were significantly higher that
historic time comparisons. Although scaup declined -25% since last year and compared
to the ten-year mean -41%, the 2000 index is similar to the long-term average (2%).
With good to excellent habitat conditions in place, waterfowl production should be above
average in South Dakota in 2001.
2. Wetland counts in North Dakota this year were similar (2%) to those in 2000. The 2001
index is 13% below the ten-year mean and similar (3%) to the long-term average. Gains
in wetland numbers realized in eastern regions were probably off-set by drier conditions
in the west. At the start of the survey, current year vegetation development was farther
advanced than in southern South Dakota, and with CRP and residual wetland associated
cover, supplies were above average. The waterfowl breeding population for total ducks
exceeded 5.7 million birds. The 2001 index represents a -22% decrease compared to last
year, but again is above the ten-year (35%) and long-term (108%) averages. This year’s
mallard index (1.484 million) is second highest of record and is similar to the 1999 and
2000 indices. As in South Dakota, pintails (43%) responded in a positive way to the
good/excellent habitat conditions offered in North Dakota. The pintail index is 32% and
9% above the ten-year and long-term means. Echoing the trend in South Dakota, North
Dakota scaup decreased -27% since last year but are 28% and 94% above the respective
ten-year and long-term comparisons. With mostly good to excellent habitat conditions in
North Dakota, waterfowl production is expected to again be above average in 2001.
John W. Solberg and Sue Thomas
July 2001
Table 1. Status of waterfowl breeding population estimates (thousands, adjusted for visibility bias) by species and stratum with
comparisons against the previous year, the previous 10-year mean, and the long-term mean (from 1959) for South Dakota.
Stratum % Change From
Species/Ponds 44 48 49 2001 Total 2000 Total 10-Year Mean Long-Term
Mean
2000 10-Year Mean Long-Term
Mean
Ducks
Dabblers
Mallard 135.8 654.3 250.3 1040.5 1108.4 815.4 456.4 -6.1% 27.6% 128.0%
Am. black duck 0.0 0.0 0.0 0.0 0.0 0.0 0.0 -- -- -100.0%
Gadwall 132.1 322.0 54.8 508.9 636.2 474.9 218.5 -20.0% 7.2% 132.9%
Am. wigeon 38.4 11.7 3.5 53.5 69.9 53.8 39.4 -23.4% -0.4% 35.9%
Am. green-winged
teal
26.2 29.5 14.0 69.8 51.6 40.7 28.8 35.3% 71.4% 142.1%
Blue-winged teal 36.7 1192.8 379.1 1608.7 1576.9 1282.7 819.3 2.0% 25.4% 96.3%
N. shoveler 32.5 359.0 70.4 461.9 226.8 259.0 185.1 103.7% 78.4% 149.6%
N. pintail 44.7 300.4 40.3 385.4 200.5 204.1 220.0 92.2% 88.8% 75.2%
Subtotal 446.5 2869.8 812.4 4128.7 3870.3 3130.5 1967.5 6.7% 31.9% 109.8%
Divers
Redhead 0.0 42.8 8.2 51.0 33.0 55.9 47.3 54.4% -8.9% 7.8%
Canvasback 0.5 3.5 1.1 5.1 6.7 6.9 6.4 -24.1% -26.9% -20.4%
Scaups 4.3 31.7 8.5 44.5 59.1 75.5 43.4 -24.6% -41.0% 2.5%
Ring-necked duck 1.9 5.9 0.9 8.7 10.8 17.3 8.2 -19.7% -49.7% 6.4%
Goldeneyes 0.0 0.0 0.0 0.0 0.0 0.6 0.3 -- -100.0% -100.0%
Bufflehead 0.6 0.0 0.0 0.6 0.4 3.2 1.5 57.6% -81.1% -60.2%
Ruddy Duck 0.0 42.7 16.1 58.8 65.9 32.2 30.9 -10.7% 82.9% 90.6%
Subtotal 7.3 126.7 34.7 168.7 175.9 191.7 138.0 -4.1% -12.0% 22.2%
Miscellaneous
Oldsquaw 0.0 0.0 0.0 0.0 0.0 0.0 0.0 -- -- --
Eiders 0.0 0.0 0.0 0.0 0.0 0.0 0.0 -- -- --
Scoters 0.0 0.0 0.0 0.0 0.0 0.2 0.0 -- -100.0% -100.0%
Mergansers 3.2 0.5 0.0 3.7 2.9 3.2 1.5 27.8% 14.3% 140.1%
Subtotal 3.2 0.5 0.0 3.7 2.9 3.4 1.6 27.8% 8.9% 134.3%
Total Ducks 457.0 2997.0 847.1 4301.1 4049.1 3325.6 2107.1 6.2% 29.3% 104.1%
Canada Goose 24.0 110.6 35.3 169.9 165.3 77.0 26.2 2.8% 120.6% 548.9%
Am. coot 0.7 95.7 45.2 141.7 300.9 346.9 202.7 -52.9% -59.2% -30.1%
Ponds 105.3 562.9 320.9 989.1 627.6 719.5 526.9 57.6% 37.5% 87.7%
Table 2. Long-term trend in adjusted May pond estimates (thousands) by stratum with
comparisons against the previous year, the previous 10-year mean, and the long-term
mean (from 1974) for South Dakota. Estimates prior to 1974 were not adjusted for
visibility bias.
Stratum
Year 44 48 49 Total
1961 33.1 48.1 34.2 115.4
1962 69.5 152.3 95.7 317.4
1963 80.2 142.2 106.9 329.3
1964 62.0 79.3 56.8 198.0
1965 84.5 100.3 53.0 237.8
1966 94.5 143.6 79.7 317.8
1967 90.2 132.4 66.5 289.0
1968 71.8 146.0 61.1 278.9
1969 156.5 263.5 111.6 531.6
1970 161.3 183.3 58.9 403.4
1971 146.4 132.7 85.4 364.4
1972 205.5 263.8 108.1 577.4
1973 153.4 126.1 82.4 362.0
1974 68.0 186.0 125.4 379.4
1975 151.0 236.4 108.3 495.7
1976 92.9 121.8 93.1 307.8
1977 84.7 114.5 73.0 272.3
1978 212.3 307.4 131.5 651.2
1979 82.0 214.6 148.6 445.3
1980 66.8 108.4 88.3 263.5
1981 64.3 58.8 40.0 163.0
1982 148.1 176.7 73.7 398.4
1983 104.3 189.4 142.6 436.4
1984 142.8 262.4 189.4 594.6
1985 116.7 183.8 124.4 425.0
1986 216.7 260.5 132.2 609.4
1987 194.9 216.4 105.9 517.3
1988 92.5 99.9 114.4 306.8
1989 195.4 222.0 86.7 504.1
1990 124.0 79.4 56.7 260.0
1991 106.5 113.1 69.5 289.1
1992 107.5 96.8 61.6 265.8
1993 141.1 334.7 225.0 700.7
1994 281.1 356.5 180.9 818.4
1995 279.4 458.2 195.9 933.4
1996 324.4 418.2 172.2 914.8
1997 278.8 478.8 167.5 925.1
1998 195.3 337.8 162.0 695.1
1999 157.4 618.1 249.4 1025.0
2000 161.3 324.7 141.6 627.6
2001 105.3 562.9 320.9 989.1
10-year Mean 203.3 353.7 162.6 719.5
Long-term Mean 155.2 243.5 128.1 526.9
Percent Change:
From 2000 -34.7% 73.3% 126.7% 57.6%
From 10-year Mean -48.2% 59.2% 97.4% 37.5%
From Long-term Mean -32.1% 131.1% 150.4% 87.7%
Table 3. Survey design for South Dakota, May 2001.
______________________________________________________________________________________________________________
Stratum
44 48 49 Total
______________________________________________________________________________________________________________
Survey design
Square miles in stratum 27,299 24,587 15,830 67,716
Square miles in sample 216 315 171 702
Linear miles in sample 864 1,260 684 2,808
Number of transects in sample 5 9 11 25
Number of segments in sample 48 70 38 156
Expansion factor 126.3842 78.05396 92.57309 ---
Current year coverage
Square miles in sample ` 216 315 171 702
Linear miles in sample 864 1,260 684 2,808
Number of transects in sample 5 9 11 25
Number of segments in sample 48 70 38 156
Expansion factor 126.3842 78.05396 92.57309 ---
________________________________________________________________________________________________________________
Appendix 1. Long –term trend in adjusted waterfowl breeding population estimates (thousands) in South Dakota.
Species/Ponds 1959 1960 1961 1962 1963 1964 1965 1966 1967 1968
Ducks
Dabblers
Mallard 108.2 176.6 212.1 367.3 535.8 261.1 314.5 216.3 248.2 450.7
Am. black duck 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0
Gadwall 0.0 9.9 18.9 73.9 164.0 53.6 115.4 112.9 75.1 197.8
Am. wigeon 7.1 9.6 6.1 8.1 3.1 4.4 0.0 9.6 29.7 22.6
Am. green-winged teal 0.0 0.0 2.7 10.0 2.7 0.0 0.0 7.7 9.6 23.5
Blue-winged teal 413.1 524.5 673.8 602.5 1201.5 686.3 703.6 623.9 313.7 466.1
N. shoveler 38.4 156.3 96.4 335.5 225.4 95.7 90.2 108.3 82.2 150.6
N. pintail 25.5 305.7 175.4 557.8 221.6 108.8 128.9 228.9 186.6 129.1
Subtotal 592.3 1182.5 1185.3 1955.1 2354.1 1209.9 1352.6 1307.7 945.1 1440.2
Divers
Redhead 0.0 30.1 14.3 56.4 50.5 50.4 56.4 56.7 20.1 33.4
Canvasback 2.8 1.4 2.8 2.2 2.6 5.0 2.0 6.1 3.5 2.6
Scaups 13.6 18.3 8.1 32.9 11.0 1.4 29.2 29.7 11.2 22.3
Ring-necked duck 0.0 0.0 0.0 0.0 1.0 0.0 0.0 1.4 1.1 0.0
Goldeneyes 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0
Bufflehead 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.4 0.9 0.0
Ruddy Duck 0.0 10.7 3.6 11.8 5.6 1.4 1.9 5.6 0.0 8.9
Subtotal 16.4 60.5 28.8 103.4 70.7 58.1 89.5 100.0 36.8 67.2
Miscellaneous
Oldsquaw 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0
Eiders 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0
Scoters 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0
Mergansers 0.0 0.0 0.0 0.0 0.0 0.0 0.0 1.3 0.0 0.0
Subtotal 0.0 0.0 0.0 0.0 0.0 0.0 0.0 1.3 0.0 0.0
Total Ducks 608.7 1243.0 1214.2 2058.5 2424.9 1268.1 1442.0 1409.0 982.0 1507.4
Canada Goose 0.0 0.0 0.0 0.0 0.0 0.0 0.0 2.3 0.9 0.0
Am. coot 31.1 40.4 29.3 61.0 21.0 53.4 19.3 33.8 28.0 75.7
Ponds
Species/Ponds 1969 1970 1971 1972 1973 1974 1975 1976 1977 1978
Ducks
Dabblers
Mallard 443.3 415.2 392.0 493.0 432.6 276.5 354.3 256.2 186.8 537.3
Am. black duck 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0
Gadwall 243.8 214.5 162.2 192.1 149.9 85.5 126.4 44.6 31.4 233.6
Am. wigeon 30.7 21.4 19.0 99.1 43.7 16.3 42.7 56.6 29.2 92.7
Am. green-winged teal 29.0 115.1 25.4 42.6 29.6 19.1 37.4 31.1 9.8 38.5
Blue-winged teal 742.2 706.8 654.3 1209.0 777.1 348.8 437.2 351.7 318.9 1287.3
N. shoveler 195.7 260.3 103.2 330.9 110.6 51.1 92.9 56.5 58.6 419.1
N. pintail 396.6 333.3 247.8 395.4 275.1 99.1 218.2 111.7 130.8 678.4
Subtotal 2081.2 2066.8 1603.9 2762.1 1818.6 896.5 1309.0 908.4 765.5 3287.0
Divers
Redhead 87.8 53.6 60.7 48.6 34.6 20.2 27.3 4.1 10.8 144.4
Canvasback 17.9 6.1 2.8 14.2 13.1 6.4 5.6 3.1 3.0 12.3
Scaups 12.1 74.4 7.3 41.1 19.2 13.0 12.7 45.3 16.4 73.7
Ring-necked duck 0.0 1.1 0.5 0.0 0.0 0.0 0.0 0.3 0.4 1.4
Goldeneyes 0.0 0.0 0.0 1.2 0.0 0.0 0.0 0.0 0.0 1.0
Bufflehead 0.0 0.0 0.0 1.5 0.0 0.5 0.0 0.0 0.0 0.5
Ruddy Duck 7.0 39.3 27.7 30.1 18.6 23.2 209.7 6.2 5.8 28.7
Subtotal 124.8 174.5 99.0 136.6 85.5 63.2 255.4 59.0 36.4 261.9
Miscellaneous
Oldsquaw 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0
Eiders 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0
Scoters 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0
Mergansers 0.0 0.0 0.0 0.0 0.8 0.0 0.0 0.0 0.0 0.0
Subtotal 0.0 0.0 0.0 0.0 0.8 0.0 0.0 0.0 0.0 0.0
Total Ducks 2206.0 2241.2 1702.9 2898.7 1904.9 959.7 1564.4 967.4 801.9 3548.9
Canada Goose 8.2 0.9 2.1 3.4 6.4 3.7 1.9 3.0 1.8 7.2
Am. coot 91.1 91.8 35.0 110.9 126.1 27.8 75.7 66.6 91.4 232.5
Ponds 379.4 495.7 307.8 272.3 651.2
Appendix 1 (continued). Long –term trend in adjusted waterfowl breeding population estimates (thousands) in South Dakota.
Species/Ponds 1979 1980 1981 1982 1983 1984 1985 1986 1987 1988
Ducks
Dabblers
Mallard 441.7 338.9 186.8 291.7 314.9 334.9 310.1 532.0 556.8 374.1
Am. black duck 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0
Gadwall 136.7 69.8 113.6 189.1 219.0 263.7 145.5 254.3 205.7 222.5
Am. wigeon 33.6 41.5 60.0 40.7 73.8 87.0 45.2 39.7 45.6 48.8
Am. green-winged teal 19.3 70.2 21.1 34.9 36.6 22.0 31.6 52.1 23.4 25.5
Blue-winged teal 906.0 483.3 254.1 519.9 801.8 938.8 604.5 1433.5 777.1 617.1
N. shoveler 341.8 59.3 66.7 152.4 200.0 236.9 113.2 379.8 226.9 84.4
N. pintail 280.0 119.7 53.0 204.2 223.8 263.5 165.3 389.5 212.8 118.4
Subtotal 2159.0 1182.6 755.3 1432.9 1869.9 2146.9 1415.3 3080.8 2048.2 1490.9
Divers
Redhead 50.9 28.2 22.0 45.2 82.9 111.9 35.9 64.2 34.1 19.3
Canvasback 5.6 8.0 5.9 2.2 2.3 15.8 4.6 11.5 5.7 7.6
Scaups 36.7 5.4 19.1 43.7 54.3 58.6 30.6 104.7 35.4 63.2
Ring-necked duck 0.6 1.2 2.8 7.1 59.0 17.3 1.4 18.3 14.4 5.7
Goldeneyes 0.0 0.0 0.0 1.2 2.4 0.8 0.8 0.8 0.0 0.0
Bufflehead 1.5 1.1 0.9 3.1 6.1 2.8 0.0 4.8 0.0 2.9
Ruddy Duck 16.0 21.6 67.0 84.4 88.9 48.7 23.1 69.4 28.5 3.2
Subtotal 111.3 65.5 117.8 187.0 295.9 255.8 96.5 273.6 118.1 101.8
Miscellaneous
Oldsquaw 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0
Eiders 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0
Scoters 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0
Mergansers 2.5 0.8 0.0 7.0 5.7 6.1 0.0 0.0 0.0 2.1
Subtotal 2.5 0.8 0.0 7.0 5.7 6.1 0.0 0.0 0.0 2.1
Total Ducks 2272.9 1248.9 873.1 1626.9 2171.4 2408.9 1511.8 3354.5 2166.3 1594.7
Canada Goose 4.8 3.4 9.8 23.9 13.0 19.0 15.2 12.5 17.6 57.2
Am. coot 356.1 77.1 176.8 202.7 263.5 603.7 196.5 487.5 427.3 436.4
Ponds 445.3 263.5 163.0 398.4 436.4 594.6 425.0 609.4 517.3 306.8
Species/Ponds 1989 1990 1991 1992 1993 1994 1995 1996 1997 1998
Ducks
Dabblers
Mallard 472.0 183.5 342.6 360.6 491.5 715.9 919.7 839.8 1323.2 1035.6
Am. black duck 0.0 0.2 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0
Gadwall 177.7 125.7 282.9 281.5 246.6 383.0 541.5 451.8 819.5 624.2
Am. wigeon 21.6 27.4 44.4 32.9 17.3 83.6 46.8 47.6 71.3 74.6
Am. green-winged teal 24.4 8.5 17.0 12.6 6.6 55.2 58.4 63.0 69.4 34.3
Blue-winged teal 860.2 346.3 1075.4 626.4 679.9 1383.6 1468.4 1390.9 1535.0 1573.4
N. shoveler 185.4 79.2 117.2 102.0 213.4 283.5 350.0 287.6 414.3 230.3
N. pintail 148.3 63.4 69.8 65.7 166.7 230.1 364.2 187.3 349.9 205.4
Subtotal 1889.5 834.3 1949.3 1481.8 1821.9 3134.8 3749.0 3268.0 4582.7 3777.8
Divers
Redhead 55.1 16.7 11.7 41.0 62.4 98.2 68.4 54.3 55.6 78.9
Canvasback 5.3 8.1 5.3 1.4 8.0 14.6 7.6 9.1 9.2 4.5
Scaups 80.4 43.5 66.8 47.9 7.3 155.2 120.9 94.6 75.6 87.4
Ring-necked duck 17.7 17.6 5.5 27.6 5.8 11.1 41.6 17.4 19.1 8.4
Goldeneyes 0.0 0.0 3.6 0.0 0.0 0.8 0.8 0.9 0.0 0.0
Bufflehead 5.0 0.5 1.2 7.5 0.0 12.0 5.9 1.2 1.3 0.6
Ruddy Duck 44.0 34.1 10.2 3.9 21.5 36.7 43.2 14.7 18.7 24.9
Subtotal 207.6 120.5 104.2 129.3 105.0 328.7 288.4 192.1 179.5 204.8
Miscellaneous
Oldsquaw 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0
Eiders 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0
Scoters 0.0 0.0 0.0 1.6 0.0 0.0 0.0 0.0 0.0 0.0
Mergansers 3.5 2.4 4.0 0.0 2.1 3.7 4.9 0.5 7.7 2.5
Subtotal 3.5 2.4 4.0 1.6 2.1 3.7 4.9 0.5 7.7 2.5
Total Ducks 2100.5 957.3 2057.5 1612.7 1929.1 3467.2 4042.3 3460.6 4769.9 3985.1
Canada Goose 65.4 46.2 44.2 48.6 37.7 46.5 55.9 73.5 86.8 99.8
Am. coot 284.7 191.5 77.4 132.8 167.2 311.0 616.9 409.9 525.7 469.0
Ponds 504.1 260.0 289.1 265.8 700.7 818.4 933.4 914.8 925.1 695.1
Appendix 1 (continued). Long –term trend in adjusted waterfowl breeding population estimates (thousands) in South Dakota.
Species/Ponds 1999 2000 2001
Ducks
Dabblers
Mallard 1016.4 1108.4 1040.5
Am. black duck 0.0 0.0 0.0
Gadwall 481.6 636.2 508.9
Am. wigeon 49.1 69.9 53.5
Am. green-winged teal 39.1 51.6 69.8
Blue-winged teal 1516.6 1576.9 1608.7
N. shoveler 364.3 226.8 461.9
N. pintail 201.9 200.5 385.4
Subtotal 3669.0 3870.3 4128.7
Divers
Redhead 56.0 33.0 51.0
Canvasback 2.9 6.7 5.1
Scaups 40.3 59.1 44.5
Ring-necked duck 25.7 10.8 8.7
Goldeneyes 0.0 0.0 0.0
Bufflehead 2.3 0.4 0.6
Ruddy Duck 82.1 65.9 58.8
Subtotal 209.4 175.9 168.7
Miscellaneous
Oldsquaw 0.0 0.0 0.0
Eiders 0.0 0.0 0.0
Scoters 0.0 0.0 0.0
Mergansers 4.0 2.9 3.7
Subtotal 4.0 2.9 3.7
Total Ducks 3882.5 4049.1 4301.1
Canada Goose 111.8 165.3 169.9
Am. coot 458.6 300.9 141.7
Ponds 1025.0 627.6 989.1
Strata 44, 48-49 Mallard
Population
100000
200000
300000
400000
500000
600000
700000
800000
900000
1000000
1100000
1200000
1300000
1400000
Year
1950 1960 1970 1980 1990 2000 2010
Strata 44, 48-49 Gadwall
Population
0
100000
200000
300000
400000
500000
600000
700000
800000
900000
Year
1950 1960 1970 1980 1990 2000 2010
Strata 44, 48-49 American wigeon
Population
0
10000
20000
30000
40000
50000
60000
70000
80000
90000
100000
Year
1950 1960 1970 1980 1990 2000 2010
Strata 44, 48-49 American green-winged teal
Population
0
10000
20000
30000
40000
50000
60000
70000
80000
90000
100000
110000
120000
Year
1950 1960 1970 1980 1990 2000 2010
Strata 44, 48-49 Blue-winged teal
Population
200000
300000
400000
500000
600000
700000
800000
900000
1000000
1100000
1200000
1300000
1400000
1500000
1600000
1700000
Year
1950 1960 1970 1980 1990 2000 2010
Strata 44, 48-49 Northern shoveler
Population
0
100000
200000
300000
400000
500000
Year
1950 1960 1970 1980 1990 2000 2010
Strata 44, 48-49 Northern pintail
Population
0
100000
200000
300000
400000
500000
600000
700000
Year
1950 1960 1970 1980 1990 2000 2010
Strata 44, 48-49 Redhead
Population
0
10000
20000
30000
40000
50000
60000
70000
80000
90000
100000
110000
120000
130000
140000
150000
Year
1950 1960 1970 1980 1990 2000 2010
Strata 44, 48-49 Canvasback
Population
1000
2000
3000
4000
5000
6000
7000
8000
9000
10000
11000
12000
13000
14000
15000
16000
17000
18000
Year
1950 1960 1970 1980 1990 2000 2010
Strata 44, 48-49 Scaups
Population
0
10000
20000
30000
40000
50000
60000
70000
80000
90000
100000
110000
120000
130000
140000
150000
160000
Year
1950 1960 1970 1980 1990 2000 2010
Strata 44, 48-49 Canada Goose
Population
0
10000
20000
30000
40000
50000
60000
70000
80000
90000
100000
110000
120000
130000
140000
150000
160000
170000
Year
1950 1960 1970 1980 1990 2000 2010
Strata 44, 48-49 American coot
Population
0
100000
200000
300000
400000
500000
600000
700000
Year
1950 1960 1970 1980 1990 2000 2010
Strata 44, 48-49 Ponds
Population
100000
200000
300000
400000
500000
600000
700000
800000
900000
1000000
1100000
Year
1960 1970 1980 1990 2000 2010
Strata 44, 48-49 Total Ducks
Population
0
1000000
2000000
3000000
4000000
5000000
Year
1950 1960 1970 1980 1990 2000 2010
Table 4. Status of waterfowl breeding population estimates (thousands, adjusted for visibility bias) by species and stratum with
comparisons against the previous year, the previous 10-year mean, and the long-term mean. (from1958) for North Dakota.
Stratum % Change From
Species/Ponds 43 45 46 47 2001
Total
2000
Total
10-Year
Mean
Long-
Term
Mean
2000 10-Year
Mean
Long-
Term
Mean
Ducks
Dabblers
Mallard 88.3 838.8 471.0 86.2 1484.3 1482.8 968.4 564.4 0.1% 53.3% 163.0%
Am. black duck 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0 -- -- --
Gadwall 91.6 429.4 246.0 13.3 780.3 1236.3 685.1 351.3 -36.9% 13.9% 122.1%
Am. wigeon 7.7 39.2 34.0 1.6 82.5 98.0 67.3 43.5 -15.8% 22.6% 89.8%
Am. green-winged teal 19.2 19.5 6.0 0.0 44.7 44.4 45.7 34.7 0.6% -2.1% 28.9%
Blue-winged teal 48.3 995.5 603.6 41.4 1688.7 2848.5 1345.0 841.2 -40.7% 25.6% 100.8%
N. shoveler 33.2 466.8 163.9 18.6 682.5 647.0 413.5 263.4 5.5% 65.0% 159.1%
N. pintail 37.6 241.4 95.1 2.9 377.0 262.8 286.1 345.2 43.5% 31.8% 9.2%
Subtotal 326.0 3030.4 1619.6 164.0 5140.0 6619.8 3811.0 2443.5 -22.4% 34.9% 110.4%
Divers
Redhead 8.0 170.4 37.5 10.5 226.4 306.1 193.7 134.9 -26.0% 16.9% 67.8%
Canvasback 0.8 62.1 3.6 0.0 66.5 20.8 38.4 28.9 219.1% 73.2% 130.1%
Scaups 6.6 57.8 66.0 0.0 130.3 178.2 102.2 67.1 -26.9% 27.5% 94.2%
Ring-necked duck 2.6 3.9 6.9 0.0 13.3 6.2 13.3 7.9 114.4% 0.1% 68.6%
Goldeneyes 0.0 0.0 0.0 0.0 0.0 1.3 0.2 0.2 -100.0% -100.0% -100.0%
Bufflehead 0.5 4.2 0.5 0.0 5.2 3.2 2.6 1.2 61.3% 103.2% 322.3%
Ruddy Duck 4.5 124.1 56.4 0.0 185.0 212.3 108.8 89.1 -12.8% 70.1% 107.6%
Subtotal 23.0 422.3 170.8 10.5 626.7 728.1 459.0 329.4 -13.9% 36.5% 90.3%
Miscellaneous
Oldsquaw 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0 -- -- --
Eiders 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0 -- -- --
Scoters 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0 -- -100.0% -100.0%
Mergansers 0.0 0.0 0.7 0.0 0.7 7.5 1.5 0.9 -91.1% -56.7% -22.6%
Subtotal 0.0 0.0 0.7 0.0 0.7 7.5 1.6 0.9 -91.1% -58.0% -23.6%
Total Ducks 349.0 3452.8 1791.1 174.5 5767.4 7355.4 4271.7 2773.7 -21.6% 35.0% 107.9%
Canada Goose 27.4 81.7 74.0 1.0 184.1 161.6 63.2 19.2 14.0% 191.5% 856.8%
Am. coot 62.1 197.8 55.9 3.9 319.6 912.6 806.8 402.6 -65.0% -60.4% -20.6%
Ponds 86.2 414.9 222.1 26.9 750.2 734.3 859.1 726.7 2.2% -12.7% 3.2%
Table 5. Long-term trend in adjusted May pond estimates (thousands) by stratum with
comparisons against the previous year, the previous 10-year mean, and the long-term mean (from
1974) for North Dakota. Estimates prior to 1974 were not adjusted for visibility bias.
Stratum
Year 43 45 46 47 Total
1961 11.8 38.2 26.3 9.6 85.8
1962 25.5 132.6 97.1 17.4 272.6
1963 41.6 206.2 150.9 17.4 416.1
1964 29.4 107.2 41.4 10.4 188.5
1965 51.3 199.4 103.8 13.9 368.4
1966 55.7 265.5 182.9 36.5 540.6
1967 50.1 311.7 168.8 29.9 560.6
1968 54.0 141.1 109.9 11.7 316.8
1969 89.5 326.2 169.9 31.6 617.2
1970 101.5 473.0 152.4 29.2 756.1
1971 109.4 365.5 87.4 17.0 579.3
1972 130.9 338.2 148.0 35.3 652.4
1973 88.4 167.4 54.0 11.8 321.6
1974 64.7 950.9 179.3 57.3 1252.2
1975 104.9 703.4 286.0 41.4 1135.8
1976 84.0 505.1 221.8 37.4 848.2
1977 88.2 179.2 60.1 12.8 340.3
1978 123.7 304.2 195.2 14.2 637.3
1979 87.0 447.4 268.5 32.9 835.8
1980 65.4 179.5 89.4 11.1 345.5
1981 70.3 208.4 55.2 9.7 343.5
1982 140.5 443.2 183.4 19.0 786.0
1983 80.0 398.1 147.5 23.3 648.9
1984 113.9 554.6 269.2 27.7 965.4
1985 115.0 355.5 126.6 17.6 614.6
1986 120.0 381.2 201.7 25.8 728.8
1987 134.5 281.2 170.4 15.1 601.1
1988 94.7 135.4 74.8 8.7 313.6
1989 116.4 198.6 117.5 15.5 448.0
1990 72.8 64.9 39.5 8.0 185.2
1991 72.4 59.1 36.1 7.7 175.3
1992 119.6 146.7 47.9 9.4 323.6
1993 106.4 167.3 163.0 18.4 455.1
1994 203.2 412.0 275.5 27.9 918.7
1995 197.0 581.6 348.0 34.1 1160.6
1996 193.9 545.0 386.1 55.8 1180.7
1997 163.0 558.8 393.3 42.4 1157.6
1998 159.4 462.4 359.0 64.0 1044.8
1999 137.5 895.5 361.3 45.6 1439.9
2000 105.1 363.2 242.4 23.6 734.3
2001 86.2 414.9 222.1 26.9 750.2
10-year Mean 145.7 419.2 261.3 32.9 859.1
Long-term Mean 116.0 388.2 196.2 26.2 726.7
Percent Change:
From 2000 -17.9% 14.2% -8.4% 13.8% 2.2%
From 10-year Mean -40.8% -1.0% -15.0% -18.3% -12.7%
From Long-term Mean -25.7% 6.9% 13.2% 2.7% 3.2%
Table 6. Survey design for North Dakota, May 2001.
______________________________________________________________________________________________________________________
Stratum
______________________________________
43 45 46 47 Total
______________________________________________________________________________________________________________________
Survey design
Square miles in stratum 19,835 26,625 14,238 7,821 68,519
Square miles in sample 175.5 310.5 270.0 45.0 801.0
Linear miles in sample 702 1,242 1,080 180 3,204
Number of transects in sample 5 7 8 6 26
Number of segments in sample 39 69 60 10 178
Expansion factor 113.0199 85.74879 52.73333 173.8000 ---
Current year coverage
Square miles in sample 175.5 310.5 270.0 45.0 801.0
Linear miles in sample 702 1,242 1,080 180 3,204
Number of transects in sample 5 7 8 6 26
Number of segments in sample 39 69 60 10 178
Expansion factor 113.0199 85.74879 52.73333 173.8000 ---
______________________________________________________________________________________________________________________
Appendix 2. Long-term trend in adjusted waterfowl breeding population estimates (thousands) in North Dakota.
Species/Ponds 1958 1959 1960 1961 1962 1963 1964 1965 1966 1967
Ducks
Dabblers
Mallard 402.4 162.2 288.5 225.9 238.1 512.8 271.1 430.2 507.1 545.0
Am. black duck 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0
Gadwall 44.8 13.4 85.2 56.4 156.2 213.8 86.0 226.8 269.5 216.2
Am. wigeon 24.7 24.9 22.8 5.0 3.8 16.4 4.6 5.9 18.6 27.9
Am. green-winged teal 4.5 0.0 0.0 6.8 0.0 2.2 0.0 3.3 60.9 26.9
Blue-winged teal 528.7 316.4 519.5 295.6 755.2 686.6 584.5 913.5 1041.7 1106.1
N. shoveler 62.9 45.3 184.8 106.8 271.5 221.0 102.8 289.4 290.4 403.8
N. pintail 330.4 62.8 632.7 244.9 429.6 320.7 230.3 478.6 495.3 544.9
Subtotal 1398.3 625.0 1733.4 941.4 1854.5 1973.5 1279.2 2347.6 2683.5 2870.8
Divers
Redhead 34.1 15.3 88.9 39.3 91.2 97.4 58.5 117.1 203.1 163.1
Canvasback 30.7 6.9 13.2 3.1 2.2 14.7 17.2 19.0 53.6 26.5
Scaups 11.7 22.1 40.7 18.3 77.7 15.1 3.0 14.0 15.5 22.1
Ring-necked duck 0.0 0.0 2.9 0.0 0.0 0.9 0.0 0.0 2.5 0.0
Goldeneyes 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0 1.2 0.0
Bufflehead 0.0 0.0 0.0 0.0 0.0 0.1 0.0 0.1 0.1 0.0
Ruddy Duck 1.6 23.8 44.3 23.3 27.5 18.2 5.4 9.0 33.4 41.8
Subtotal 78.1 68.1 190.0 84.0 198.6 146.3 84.1 159.3 309.4 253.6
Miscellaneous
Oldsquaw 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0
Eiders 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0
Scoters 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0
Mergansers 0.0 0.0 0.0 0.0 0.0 0.2 0.0 0.2 0.2 0.0
Subtotal 0.0 0.0 0.0 0.0 0.0 0.2 0.0 0.2 0.2 0.0
Total Ducks 1476.4 693.1 1923.4 1025.5 2053.1 2120.0 1363.3 2507.2 2993.2 3124.4
Canada Goose 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.1 0.1 0.0
Am. coot 59.0 94.4 82.0 51.1 104.0 47.4 14.2 93.8 150.5 203.3
Ponds
Species/Ponds 1968 1969 1970 1971 1972 1973 1974 1975 1976 1977
Ducks
Dabblers
Mallard 434.6 462.6 736.6 769.3 674.0 547.2 458.4 566.5 368.0 292.1
Am. black duck 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0
Gadwall 352.9 323.1 373.9 372.2 353.6 223.2 213.6 330.1 76.5 103.0
Am. wigeon 8.3 40.5 30.0 28.1 29.1 36.0 44.1 72.8 62.3 31.7
Am. green-winged teal 12.4 67.0 138.6 23.4 51.0 38.0 75.0 59.4 17.4 7.4
Blue-winged teal 749.7 902.9 712.7 1238.1 780.3 588.7 1171.3 1051.4 357.0 282.2
N. shoveler 194.8 304.0 454.9 219.4 289.9 129.7 219.5 225.2 89.7 71.2
N. pintail 169.4 693.7 831.6 690.0 749.1 257.1 487.1 455.6 208.6 91.1
Subtotal 1922.2 2793.9 3278.5 3340.4 2926.9 1819.9 2669.0 2761.1 1179.5 878.6
Divers
Redhead 93.3 177.1 153.5 123.7 126.9 94.6 110.7 214.8 63.6 31.9
Canvasback 17.3 58.9 24.7 14.7 30.2 28.5 63.0 39.3 15.3 10.3
Scaups 16.6 36.3 28.3 28.2 30.4 41.9 37.3 70.3 54.1 19.7
Ring-necked duck 0.0 0.6 2.8 1.1 0.7 0.0 0.6 1.2 1.1 1.4
Goldeneyes 0.0 0.0 0.0 0.0 1.1 0.0 0.0 0.0 0.0 0.0
Bufflehead 0.0 0.0 1.8 0.0 2.6 0.5 0.0 0.0 0.7 0.0
Ruddy Duck 15.5 45.2 86.0 47.0 55.1 40.7 167.0 125.1 22.8 21.1
Subtotal 142.8 318.0 297.1 214.7 247.1 206.1 378.5 450.7 157.7 84.4
Miscellaneous
Oldsquaw 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0
Eiders 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0
Scoters 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0
Mergansers 0.0 2.9 0.0 0.0 1.4 0.7 0.7 0.0 0.0 0.0
Subtotal 0.0 2.9 0.0 0.0 1.4 0.7 0.7 0.0 0.0 0.0
Total Ducks 2065.0 3114.7 3575.6 3555.1 3175.4 2026.7 3048.2 3211.8 1337.2 963.0
Canada Goose 0.0 0.0 0.0 0.0 0.0 3.8 0.9 3.3 2.2 3.8
Am. coot 127.5 131.3 192.3 147.7 178.8 124.7 368.9 512.9 104.2 74.8
Ponds 1252.2 1135.8 848.2 340.3
Appendix 2 (continued). Long-term trend in adjusted waterfowl breeding population estimates (thousands) in North Dakota.
Species/Ponds 1978 1979 1980 1981 1982 1983 1984 1985 1986 1987
Ducks
Dabblers
Mallard 506.6 641.4 485.4 308.6 466.5 398.9 550.3 361.4 487.8 582.6
Am. black duck 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0
Gadwall 243.9 369.2 224.3 255.6 381.2 435.0 528.8 274.0 287.7 275.9
Am. wigeon 69.4 47.4 84.0 119.2 41.5 45.1 38.7 58.9 30.9 44.1
Am. green-winged teal 20.5 25.4 92.4 39.2 52.6 16.4 16.2 58.9 20.1 33.5
Blue-winged teal 737.4 826.5 888.4 252.8 906.3 545.7 861.0 547.0 871.8 579.4
N. shoveler 277.5 447.3 181.9 264.1 377.4 194.3 273.3 153.2 244.7 255.5
N. pintail 588.5 517.3 291.8 135.2 369.4 329.4 375.5 198.9 260.0 191.6
Subtotal 2443.7 2874.5 2248.2 1374.7 2594.9 1964.8 2643.7 1652.3 2202.9 1962.8
Divers
Redhead 191.8 198.3 122.7 75.2 258.2 226.3 170.3 116.9 103.5 99.0
Canvasback 17.0 42.7 28.5 31.9 32.4 12.4 50.9 20.1 36.3 28.7
Scaups 99.8 199.2 47.7 107.5 103.9 92.6 120.8 102.1 129.4 91.4
Ring-necked duck 2.2 8.4 3.6 0.0 11.6 103.0 12.2 3.5 11.6 3.2
Goldeneyes 0.0 0.0 0.0 0.0 0.0 2.5 1.4 0.0 0.0 1.0
Bufflehead 1.0 2.4 1.4 1.0 0.7 3.7 7.1 0.5 0.8 0.0
Ruddy Duck 123.3 98.0 111.4 237.6 357.1 184.8 251.8 111.9 170.1 113.9
Subtotal 435.0 549.0 315.4 453.2 763.9 625.2 614.4 355.0 451.7 337.2
Miscellaneous
Oldsquaw 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0
Eiders 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0
Scoters 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0
Mergansers 0.0 0.0 0.0 0.0 0.3 6.3 2.7 0.5 0.0 0.5
Subtotal 0.0 0.0 0.0 0.0 0.3 6.3 2.7 0.5 0.0 0.5
Total Ducks 2878.7 3423.5 2563.6 1827.9 3359.1 2596.3 3260.8 2007.8 2654.6 2300.5
Canada Goose 0.9 2.7 3.7 7.4 22.4 10.5 13.7 11.3 17.0 12.3
Am. coot 389.6 1358.1 396.0 374.7 561.3 411.0 898.9 309.7 313.2 530.3
Ponds 637.3 835.8 345.5 343.5 786.0 648.9 965.4 614.6 728.8 601.1
Species/Ponds 1988 1989 1990 1991 1992 1993 1994 1995 1996 1997
Ducks
Dabblers
Mallard 354.9 404.0 142.2 261.8 364.1 374.1 900.7 1063.9 1100.5 1377.7
Am. black duck 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0
Gadwall 294.9 296.3 296.0 197.9 388.7 285.8 433.3 757.4 806.3 893.8
Am. wigeon 40.8 15.6 22.9 20.9 44.1 13.9 71.4 92.0 78.9 83.2
Am. green-winged teal 28.3 9.5 26.7 9.1 14.1 9.0 60.5 45.9 90.6 79.0
Blue-winged teal 553.9 338.5 230.4 233.4 401.4 303.1 1088.8 1463.1 1764.1 1544.6
N. shoveler 118.4 158.7 67.1 75.2 114.7 175.1 507.8 573.6 653.8 492.2
N. pintail 149.7 109.0 61.8 49.3 112.1 126.9 375.5 424.9 351.5 418.1
Subtotal 1541.1 1331.5 847.1 847.7 1439.2 1288.0 3438.0 4420.8 4845.8 4888.7
Divers
Redhead 55.2 133.4 17.0 14.7 78.8 102.2 155.0 218.2 257.9 216.5
Canvasback 19.2 39.2 10.1 8.6 17.3 19.8 56.1 42.0 58.6 69.2
Scaups 83.0 38.8 43.6 89.9 23.0 36.6 109.6 108.5 91.5 115.5
Ring-necked duck 10.5 10.9 9.6 5.0 10.3 0.4 15.7 44.4 12.1 11.2
Goldeneyes 0.0 0.0 0.0 0.0 0.0 0.0 0.7 0.0 0.0 0.0
Bufflehead 0.5 2.1 0.5 3.2 3.3 2.5 4.7 3.6 1.8 2.0
Ruddy Duck 12.6 55.3 62.5 14.0 29.5 33.9 105.6 78.6 72.8 180.2
Subtotal 181.1 279.7 143.3 135.5 162.0 195.4 447.3 495.3 494.7 594.6
Miscellaneous
Oldsquaw 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0
Eiders 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0
Scoters 0.0 0.0 0.0 0.5 0.0 0.0 0.0 0.0 0.0 0.0
Mergansers 0.0 0.7 4.3 3.2 0.0 0.3 0.5 1.4 0.3 0.9
Subtotal 0.0 0.7 4.3 3.7 0.0 0.3 0.5 1.4 0.3 0.9
Total Ducks 1722.2 1611.9 994.7 986.9 1601.3 1483.7 3885.8 4917.5 5340.8 5484.3
Canada Goose 18.0 34.9 26.6 18.0 32.1 21.2 40.9 55.5 51.8 69.5
Am. coot 429.1 246.8 161.7 58.1 84.1 113.9 608.0 1675.9 1241.9 1715.3
Ponds 313.6 448.0 185.2 175.3 323.6 455.1 918.7 1160.6 1180.7 1157.6
Appendix 2 (continued). Long-term trend in adjusted waterfowl breeding population estimates (thousands) in North Dakota.
Species/Ponds 1998 1999 2000 2001
Ducks
Dabblers
Mallard 1267.7 1490.9 1482.8 1484.3
Am. black duck 0.0 0.0 0.0 0.0
Gadwall 932.9 918.4 1236.3 780.3
Am. wigeon 101.0 69.1 98.0 82.5
Am. green-winged teal 48.4 55.5 44.4 44.7
Blue-winged teal 1734.6 2068.0 2848.5 1688.7
N. shoveler 360.6 535.0 647.0 682.5
N. pintail 281.2 459.1 262.8 377.0
Subtotal 4726.4 5596.1 6619.8 5140.0
Divers
Redhead 327.6 259.8 306.1 226.4
Canvasback 49.4 42.3 20.8 66.5
Scaups 148.0 120.8 178.2 130.3
Ring-necked duck 7.0 20.6 6.2 13.3
Goldeneyes 0.0 0.0 1.3 0.0
Bufflehead 1.1 0.3 3.2 5.2
Ruddy Duck 143.3 217.3 212.3 185.0
Subtotal 676.4 661.0 728.1 626.7
Miscellaneous
Oldsquaw 0.0 0.0 0.0 0.0
Eiders 0.0 0.0 0.0 0.0
Scoters 0.0 0.0 0.0 0.0
Mergansers 0.5 0.7 7.5 0.7
Subtotal 0.5 0.7 7.5 0.7
Total Ducks 5403.3 6257.9 7355.4 5767.4
Canada Goose 76.5 104.5 161.6 184.1
Am. coot 767.9 889.9 912.6 319.6
Ponds 1044.8 1439.9 734.3 750.2
Strata 43, 45-47 Mallard
Population
100000
200000
300000
400000
500000
600000
700000
800000
900000
1000000
1100000
1200000
1300000
1400000
1500000
Year
1950 1960 1970 1980 1990 2000 2010
Strata 43, 45-47 Gadwall
Population
0
100000
200000
300000
400000
500000
600000
700000
800000
900000
1000000
1100000
1200000
1300000
Year
1950 1960 1970 1980 1990 2000 2010
Strata 43, 45-47 American wigeon
Population
0
10000
20000
30000
40000
50000
60000
70000
80000
90000
100000
110000
120000
Year
1950 1960 1970 1980 1990 2000 2010
Strata 43, 45-47 American green-winged teal
Population
0
10000
20000
30000
40000
50000
60000
70000
80000
90000
100000
110000
120000
130000
140000
Year
1950 1960 1970 1980 1990 2000 2010
Strata 43, 45-47 Blue-winged teal
Population
0
1000000
2000000
3000000
Year
1950 1960 1970 1980 1990 2000 2010
Strata 43, 45-47 Northern shoveler
Population
0
100000
200000
300000
400000
500000
600000
700000
Year
1950 1960 1970 1980 1990 2000 2010
Strata 43, 45-47 Northern pintail
Population
0
100000
200000
300000
400000
500000
600000
700000
800000
900000
Year
1950 1960 1970 1980 1990 2000 2010
Strata 43, 45-47 Redhead
Population
0
100000
200000
300000
400000
Year
1950 1960 1970 1980 1990 2000 2010
Strata 43, 45-47 Canvasback
Population
0
10000
20000
30000
40000
50000
60000
70000
Year
1950 1960 1970 1980 1990 2000 2010
Strata 43, 45-47 Scaups
Population
0
10000
20000
30000
40000
50000
60000
70000
80000
90000
100000
110000
120000
130000
140000
150000
160000
170000
180000
190000
200000
Year
1950 1960 1970 1980 1990 2000 2010
Strata 43, 45-47 Canada Goose
Population
0
10000
20000
30000
40000
50000
60000
70000
80000
90000
100000
110000
120000
130000
140000
150000
160000
170000
180000
190000
Year
1950 1960 1970 1980 1990 2000 2010
Strata 43, 45-47 American coot
Population
0
100000
200000
300000
400000
500000
600000
700000
800000
900000
1000000
1100000
1200000
1300000
1400000
1500000
1600000
1700000
1800000
Year
1950 1960 1970 1980 1990 2000 2010
Strata 43, 45-47 Ponds
Population
100000
200000
300000
400000
500000
600000
700000
800000
900000
1000000
1100000
1200000
1300000
1400000
1500000
Year
1960 1970 1980 1990 2000 2010
Strata 43, 45-47 Total Ducks
Population
0
1000000
2000000
3000000
4000000
5000000
6000000
7000000
8000000
Year
1950 1960 1970 1980 1990 2000 2010